In pulmonary arterial hypertension, increased shear stress from increased flow, hypoxia, inflammation, and altered bone morphogenic protein receptor 2 (BMPR2) signaling can drive macrophage-mediated inflammation, thereby triggering extracellular matrix accumulation and smooth muscle cell proliferation in pulmonary vascular remodeling [4, 43, 44]. This evidence concerns the gene BMPR2 and pulmonary arterial hypertension.